The invention relates to a gearing mechanism, in particular a worm gearing mechanism for devices for power-operated adjustment of elements of a motor vehicle. Specifically, the invention relates to the field of gearing mechanisms for axial drives, in particular spindle motors, in devices for adjusting seats or the like.
DE 103 44 211 A1 discloses a device for maintaining the position of an armature shaft, mounted in a rotatable or axially displaceable fashion, of an electric motor. In said document, a wrap-around body is arranged around the shaft, it being possible to apply a force to said wrap-around body in order to bring about frictional engagement between the wrap-around body and a surface of the armature shaft. This force for maintaining a position is applied by an actuator which can be actively actuated and is connected to one end of the wrap-around body.
The device which is known from DE 103 44 211 A1 has the disadvantage that active actuation of the actuator is necessary, with the result that the configuration of the device is relatively complex. Additional components, in particular the actuator and elements for actuating the actuator, are also necessary.
DE 10 2005 012 938 A1 discloses a gearing mechanism drive unit having a load torque lock. The known gearing mechanism drive unit is particularly suitable for a window lifter drive. The known gearing mechanism drive unit has an electric motor which drives a gearing mechanism. The load torque lock locks the torques applied by an output-side clutch element. In this case the load torque lock has a wrap spring. However, this wrap spring is arranged on a rotationally fixed shaft. The wrap spring engages in a gear wheel which is driven on the drive side by a rotor shaft of the electric motor.